King’s Lynn Festival officials, who had organised the talk with the Royal Geographical Society, said the talk has been cancelled as it in unsure when he will be back in the UK.

It is hoped that the talk will be rescheduled soon and that there will be a new date in the next two weeks.

Ticket holders will be able to receive a full refund by contacting the Corn Exchange Box Office.

Benedict Allen – Adventures in Paradise was set to be a highlight of the King’s Lynn Festival’s winter season.

Benedict Allen. Photo: SUBMITTED.

Mr Allen was reported missing on Wednesday, but by Thursday, those close to him said he had been sighted near an airstrip.

BBC security correspondent Frank Gardner, who had travelled with Mr Allen to Papua New Guinea previously, said on Twitter: “UK explorer @benedictallen has been sighted, ‘alive and well’ nr airstrip in Papua New Guinea after being reported missing while trekking.”

It is now understood that Mr Allen is to fly out of Papua New Guinea today (Friday, November 17) via helicopter and is expected to fly home tomorrow.

A post on the King’s Lynn Festival website this afternoon said: “As Benedict Allen’s arrival date back in the UK has still not been confirmed, the King’s Lynn Festival and the Royal Geographical Society have today made the joint decision to cancel his talk, due to be held at the Guildhall of St George on Tuesday 21 November at 7.30pm.

“We intend to reschedule the talk as soon as possible, and hope to announce the new date within the next two weeks.

Alison Croose, chairman of King’s Lynn Festival, said she first heard the news of Mr Allen’s disappearance on the radio on Wednesday morning.

Later on Wednesday, Mrs Croose said: “His sister was interviewed this morning and she said some time ago, he did disappear there once before.”

King’s Lynn Festival administrator Ema Holman said on Thursday: “We have spoken to the Royal Geographical Society this morning and he’s around and alive which is fantastic news, but unfortunately he is still uncontactable and he hasn’t got on a plane as yet.

“Whenever the talk does happen, he will have a great tale to tell. I know he loves doing his talks and we are really looking forward to having him.”